Hej, this is the next attempt adding support for the DART found in Apple's M1 Pro/Max/Ultra. This adds a separate io-pgtable implementation for DART. As already mentioned in v2 the pte format is not fully compatible with io-pgtable-arm. Especially the 2nd least significant bit is used and is not available to tag tables/pages. io-pgtable-dart.c is copied from io-pgtable-arm.c and support for unused features is removed. Support for 4k IO pages is left for A7 to A11 SoCs as there's work underway to run Linux on them. The incompatibilities between both Apple DART pte seems manageable in their own io-pgtable implementation. A short list of the known differences: - the physical addresses are shifted left by 4 bits and and have 2 more bits inside the PTE entries - the read/write protection flags are at a different position - the subpage protection feature is now mandatory. For Linux we can just configure it to always allow access to the entire page. - BIT(1) tags "uncached" mappings (used for the display controller) There is second type of DART (t8110) present on M1 Pro/Max SoCs which uses the same PTE format as t6000. Changes in v5: - collected Sven's ack - minor fixes in "iommu/io-pgtable: Move Apple DART support to its own file" Changes in v4: - split dart and io-pgtable-dart build to allow building dart as module - add missing "SELECT IOMMU_IO_PGTABLE" - made map/unmap_pages/iova_to_phys inon-recursive - replace pgd concatenation with multiple table handling - simplified config and page size checks - collected Robin's Ack Changes in v3: - move APPLE_DART to its own io-pgtable implementation, copied from io-pgtable-arm and simplified Changes in v2: - added Rob's Acked-by: - add APPLE_DART2 io-pgtable format Janne Grunau (1): iommu/io-pgtable: Move Apple DART support to its own file Sven Peter (4): dt-bindings: iommu: dart: add t6000 compatible iommu/io-pgtable: Add DART subpage protection support iommu/io-pgtable-dart: Add DART PTE support for t6000 iommu: dart: Support t6000 variant .../devicetree/bindings/iommu/apple,dart.yaml | 4 +- MAINTAINERS | 1 + drivers/iommu/Kconfig | 13 +- drivers/iommu/Makefile | 1 + drivers/iommu/apple-dart.c | 24 +- drivers/iommu/io-pgtable-arm.c | 63 --- drivers/iommu/io-pgtable-dart.c | 470 ++++++++++++++++++ drivers/iommu/io-pgtable.c | 3 + include/linux/io-pgtable.h | 1 + 9 files changed, 512 insertions(+), 68 deletions(-) create mode 100644 drivers/iommu/io-pgtable-dart.c -- 2.35.1
